measuring my chamber at the case neck area?

[red-demon652]

Hello forum. Can any tell me what the tool is called if it exists,i need to measure the throat inside diamiter of my rifle.thanks

 

[Canuck-IL]

Or cast it with Cerrosafe ...
http://www.midwayusa.com/viewproduct/?productnumber=462291
/Bryan

 

[ogree]

You could use a bore mic or use some snap gauges and a regular 1-2 micrometer.

 

[red-demon652]

Ok thanks guys i like the casting idea. Im not sure what snap guages are or were i could find a bore mike. Any help there pls i apriciate it thanks.

 

[rcmodel]

Cerrosafe chamber cast:

http://www.brownells.com/.aspx/sid=...187_a_7c745_a_7c080027050_d_080027100_d_11253

rc

 

[243winxb]

SAAMI chamber drawings here > http://www.saami.org/specifications_and_information/index.cfm?page=CC

 

[Clark]

I have Cerrosafe and bore gauges, but I measure chamber necks and die necks with pin gauges.

Get the set from .061" to .250"
Get the set from .251" to .500"

Buy the cheapest sets you can find [good enough for gunsmithing] and try to buy them when they are on sale.

Enco is a cheap place to get the sets:
http://www.use-enco.com/CGI/INPDFF?PMPAGE=386&PARTPG=INLMK3&PMITEM=326-1340

To get individual pin gauges between the .001" increments for dialing in barrels in the lathe, go to MSC.

Seriously, get pin gauges sets, you can't do hand loading without them, let alone machining or gun smithing.

 

[red-demon652]

Ok thats all great info there guys i apriciare all of it wow i like it in the THR. Lots of info and great ppl. Thanks everyone

 

[twofifty]

Thanks, you'll fit rite in. We're great piple but poor spelars.

 

[Caddisflied]

Well sed, toofitty.

How accurate does the measurement need to be?
Fire a shot and measure the case.

 

[red-demon652]

I tried that measuring the cases it gave me a consistant measurement. My intentions was to find the inside diamiter of the chamber neck and see how close i was to chambering my own loads tightly like a match chamber. I olny found about 5 thousands diferenc in the fired and resized cases. So i figure in reality for a factory berrel im not hurting for accuracy problems in that area. Im using a bsa mil. Scope i fugure tharlts the jext place to look for problems.

 

[rcmodel]

I thought you wanted to measure the barrel throat?
Not the chamber neck?

Measuring a fired case will tell you exactly nothing about the barrel throat, or beginning of the rifling.

rc

 

[red-demon652]

verry true i measured the necks of the cases just as a guide not an absolute. On the other hand im getting the idea. That even if i were to get the true mesure ments of the chamber its still a factory barrel. I wouldnt significantly gain nowing the presice measurements. The brass we buy and load wouldnt be thick enough to give me that match chamer tight fit like a match gradt or chamberd barrel. So in reality i should acualy appoligize for even starting the thread. What i was seeking was a good thought but not reality. Unless i could have custome brass made for the large factory chamber my rifle has. Lol or go with an after market barrel with a mach chamber. Wich im about ready to do. Ive started a new thread to see if we can get some ideas on bullets and loads this barrel just wont group above 3000 fps with any bullet ive tried ive spent a fortune in bullets and powder a-z if any thoughts on of giving up ur secrets pls check it out in my other thread thanks.

 

[red-demon652]

Rcmodel sorry bout that i gues i wasnt sure how to spacificaly say the acual part of the throte and chamber i wanted to measure didnt meant to confuse anyone just dont. Know what im talkn about

 

[Jim K]

I am not sure what this is all about, but you DO NOT want the chamber throat too tight. In order to prevent high pressures, the case neck MUST have room to expand and release the bullet. If it is wedged in too tight, pressures go through the roof.

That is a problem some folks have encountered when necking down cases; the case neck thickens and if not reamed or turned, can cause high pressures.

Jim